Adding RDN to default

RDN should be in default:
- important project: main implementation of payment channels
https://coinmarketcap.com/currencies/raiden-network-token/
- nr 11 in volume and top 10 liquidity
https://mailchi.mp/blocklytics/uniswap-report-2019-02-05

src/ducks/addresses.js

@@ -48,6 +48,7 @@ const MAIN = {
       ['NEXO', '0x069C97DBA948175D10af4b2414969e0B88d44669'],
       ['PAX', '0xC040d51b07Aea5d94a89Bc21E8078B77366Fc6C7'],
       ['QCH', '0x755899F0540c3548b99E68C59AdB0f15d2695188'],
+      ['RDN', '0x7D03CeCb36820b4666F45E1b4cA2538724Db271C'],
       ['REN', '0x43892992B0b102459E895B88601Bb2C76736942c'],
       ['REP', '0x48B04d2A05B6B604d8d5223Fd1984f191DED51af'],
       ['RHOC', '0x394e524b47A3AB3D3327f7fF6629dC378c1494a3'],
@@ -79,6 +80,7 @@ const MAIN = {
       '0xB62132e35a6c13ee1EE0f84dC5d40bad8d815206': '0x069C97DBA948175D10af4b2414969e0B88d44669',
       '0x8E870D67F660D95d5be530380D0eC0bd388289E1': '0xC040d51b07Aea5d94a89Bc21E8078B77366Fc6C7',
       '0x687BfC3E73f6af55F0CccA8450114D107E781a0e': '0x755899F0540c3548b99E68C59AdB0f15d2695188',
+      '0x255Aa6DF07540Cb5d3d297f0D0D4D84cb52bc8e6': '0x7D03CeCb36820b4666F45E1b4cA2538724Db271C',
       '0x408e41876cCCDC0F92210600ef50372656052a38': '0x43892992B0b102459E895B88601Bb2C76736942c',
       '0x1985365e9f78359a9B6AD760e32412f4a445E862': '0x48B04d2A05B6B604d8d5223Fd1984f191DED51af',
       '0x168296bb09e24A88805CB9c33356536B980D3fC5': '0x394e524b47A3AB3D3327f7fF6629dC378c1494a3',
@@ -112,6 +114,7 @@ const MAIN = {
       ['NEXO', '0xB62132e35a6c13ee1EE0f84dC5d40bad8d815206'],
       ['PAX', '0x8E870D67F660D95d5be530380D0eC0bd388289E1'],
       ['QCH', '0x687BfC3E73f6af55F0CccA8450114D107E781a0e'],
+      ['RDN', '0x255Aa6DF07540Cb5d3d297f0D0D4D84cb52bc8e6'],
       ['REN', '0x408e41876cCCDC0F92210600ef50372656052a38'],
       ['REP', '0x1985365e9f78359a9B6AD760e32412f4a445E862'],
       ['RHOC', '0x168296bb09e24A88805CB9c33356536B980D3fC5'],